[GFS2] Add nanosecond timestamp feature

This adds a nanosecond timestamp feature to the GFS2 filesystem. Due
to the way that the on-disk format works, older filesystems will just
appear to have this field set to zero. When mounted by an older version
of GFS2, the filesystem will simply ignore the extra fields so that
it will again appear to have whole second resolution, so that its
trivially backward compatible.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

7 files changed, 39 insertions, 27 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index b784cf3c648..d16044cb023 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -772,7 +772,7 @@ static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
 			gfs2_free_data(ip, bstart, blen);
 	}
 
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 
 	gfs2_dinode_out(ip, dibh->b_data);
 
@@ -847,7 +847,7 @@ static int do_grow(struct gfs2_inode *ip, u64 size)
 	}
 
 	ip->i_di.di_size = size;
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 
 	error = gfs2_meta_inode_buffer(ip, &dibh);
 	if (error)
@@ -958,7 +958,7 @@ static int trunc_start(struct gfs2_inode *ip, u64 size)
 
 	if (gfs2_is_stuffed(ip)) {
 		ip->i_di.di_size = size;
-		ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+		ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 		gfs2_dinode_out(ip, dibh->b_data);
 		gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size);
@@ -970,7 +970,7 @@ static int trunc_start(struct gfs2_inode *ip, u64 size)
 
 		if (!error) {
 			ip->i_di.di_size = size;
-			ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+			ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 			ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG;
 			gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 			gfs2_dinode_out(ip, dibh->b_data);
@@ -1043,7 +1043,7 @@ static int trunc_end(struct gfs2_inode *ip)
 			ip->i_no_addr;
 		gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 	}
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 	ip->i_di.di_flags &= ~GFS2_DIF_TRUNC_IN_PROG;
 
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 2f154049b59..f793e31a050 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -130,7 +130,7 @@ static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 	memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 	if (ip->i_di.di_size < offset + size)
 		ip->i_di.di_size = offset + size;
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 	gfs2_dinode_out(ip, dibh->b_data);
 
 	brelse(dibh);
@@ -228,7 +228,7 @@ out:
 
 	if (ip->i_di.di_size < offset + copied)
 		ip->i_di.di_size = offset + copied;
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 	gfs2_dinode_out(ip, dibh->b_data);
@@ -1622,7 +1622,7 @@ int gfs2_dir_add(struct inode *inode, const struct qstr *name,
 				break;
 			gfs2_trans_add_bh(ip->i_gl, bh, 1);
 			ip->i_di.di_entries++;
-			ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+			ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME;
 			gfs2_dinode_out(ip, bh->b_data);
 			brelse(bh);
 			error = 0;
@@ -1708,7 +1708,7 @@ int gfs2_dir_del(struct gfs2_inode *dip, const struct qstr *name)
 		gfs2_consist_inode(dip);
 	gfs2_trans_add_bh(dip->i_gl, bh, 1);
 	dip->i_di.di_entries--;
-	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
 	gfs2_dinode_out(dip, bh->b_data);
 	brelse(bh);
 	mark_inode_dirty(&dip->i_inode);
@@ -1756,7 +1756,7 @@ int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
 		gfs2_trans_add_bh(dip->i_gl, bh, 1);
 	}
 
-	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	dip->i_inode.i_mtime = dip->i_inode.i_ctime = CURRENT_TIME;
 	gfs2_dinode_out(dip, bh->b_data);
 	brelse(bh);
 	return 0;
diff --git a/fs/gfs2/eattr.c b/fs/gfs2/eattr.c
index 40e1d37112e..2a7435b5c4d 100644
--- a/fs/gfs2/eattr.c
+++ b/fs/gfs2/eattr.c
@@ -300,7 +300,7 @@ static int ea_dealloc_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
 
 	error = gfs2_meta_inode_buffer(ip, &dibh);
 	if (!error) {
-		ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+		ip->i_inode.i_ctime = CURRENT_TIME;
 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 		gfs2_dinode_out(ip, dibh->b_data);
 		brelse(dibh);
@@ -717,7 +717,7 @@ static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
 					    (er->er_mode & S_IFMT));
 			ip->i_inode.i_mode = er->er_mode;
 		}
-		ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+		ip->i_inode.i_ctime = CURRENT_TIME;
 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 		gfs2_dinode_out(ip, dibh->b_data);
 		brelse(dibh);
@@ -852,7 +852,7 @@ static int ea_set_simple_noalloc(struct gfs2_inode *ip, struct buffer_head *bh,
 			(ip->i_inode.i_mode & S_IFMT) == (er->er_mode & S_IFMT));
 		ip->i_inode.i_mode = er->er_mode;
 	}
-	ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_ctime = CURRENT_TIME;
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 	gfs2_dinode_out(ip, dibh->b_data);
 	brelse(dibh);
@@ -1133,7 +1133,7 @@ static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
 
 	error = gfs2_meta_inode_buffer(ip, &dibh);
 	if (!error) {
-		ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+		ip->i_inode.i_ctime = CURRENT_TIME;
 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 		gfs2_dinode_out(ip, dibh->b_data);
 		brelse(dibh);
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index a31a4b80ba3..3ef0f051d07 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -178,11 +178,11 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
 	di->di_blocks = be64_to_cpu(str->di_blocks);
 	gfs2_set_inode_blocks(&ip->i_inode);
 	ip->i_inode.i_atime.tv_sec = be64_to_cpu(str->di_atime);
-	ip->i_inode.i_atime.tv_nsec = 0;
+	ip->i_inode.i_atime.tv_nsec = be32_to_cpu(str->di_atime_nsec);
 	ip->i_inode.i_mtime.tv_sec = be64_to_cpu(str->di_mtime);
-	ip->i_inode.i_mtime.tv_nsec = 0;
+	ip->i_inode.i_mtime.tv_nsec = be32_to_cpu(str->di_mtime_nsec);
 	ip->i_inode.i_ctime.tv_sec = be64_to_cpu(str->di_ctime);
-	ip->i_inode.i_ctime.tv_nsec = 0;
+	ip->i_inode.i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);
 
 	di->di_goal_meta = be64_to_cpu(str->di_goal_meta);
 	di->di_goal_data = be64_to_cpu(str->di_goal_data);
@@ -317,7 +317,7 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
 	else
 		drop_nlink(&ip->i_inode);
 
-	ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+	ip->i_inode.i_ctime = CURRENT_TIME;
 
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 	gfs2_dinode_out(ip, dibh->b_data);
@@ -648,6 +648,7 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
 	struct gfs2_dinode *di;
 	struct buffer_head *dibh;
+	struct timespec tv = CURRENT_TIME;
 
 	dibh = gfs2_meta_new(gl, inum->no_addr);
 	gfs2_trans_add_bh(gl, dibh, 1);
@@ -663,7 +664,7 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
 	di->di_nlink = 0;
 	di->di_size = 0;
 	di->di_blocks = cpu_to_be64(1);
-	di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(get_seconds());
+	di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(tv.tv_sec);
 	di->di_major = cpu_to_be32(MAJOR(dev));
 	di->di_minor = cpu_to_be32(MINOR(dev));
 	di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
@@ -693,6 +694,9 @@ static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
 	di->di_entries = 0;
 	memset(&di->__pad4, 0, sizeof(di->__pad4));
 	di->di_eattr = 0;
+	di->di_atime_nsec = cpu_to_be32(tv.tv_nsec);
+	di->di_mtime_nsec = cpu_to_be32(tv.tv_nsec);
+	di->di_ctime_nsec = cpu_to_be32(tv.tv_nsec);
 	memset(&di->di_reserved, 0, sizeof(di->di_reserved));
 
 	brelse(dibh);
@@ -1135,10 +1139,11 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 	struct gfs2_glock *gl = gh->gh_gl;
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	struct gfs2_inode *ip = gl->gl_object;
-	s64 curtime, quantum = gfs2_tune_get(sdp, gt_atime_quantum);
+	s64 quantum = gfs2_tune_get(sdp, gt_atime_quantum);
 	unsigned int state;
 	int flags;
 	int error;
+	struct timespec tv = CURRENT_TIME;
 
 	if (gfs2_assert_warn(sdp, gh->gh_flags & GL_ATIME) ||
 	    gfs2_assert_warn(sdp, !(gh->gh_flags & GL_ASYNC)) ||
@@ -1156,8 +1161,7 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 	    (sdp->sd_vfs->s_flags & MS_RDONLY))
 		return 0;
 
-	curtime = get_seconds();
-	if (curtime - ip->i_inode.i_atime.tv_sec >= quantum) {
+	if (tv.tv_sec - ip->i_inode.i_atime.tv_sec >= quantum) {
 		gfs2_glock_dq(gh);
 		gfs2_holder_reinit(LM_ST_EXCLUSIVE, gh->gh_flags & ~LM_FLAG_ANY,
 				   gh);
@@ -1168,8 +1172,8 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 		/* Verify that atime hasn't been updated while we were
 		   trying to get exclusive lock. */
 
-		curtime = get_seconds();
-		if (curtime - ip->i_inode.i_atime.tv_sec >= quantum) {
+		tv = CURRENT_TIME;
+		if (tv.tv_sec - ip->i_inode.i_atime.tv_sec >= quantum) {
 			struct buffer_head *dibh;
 			struct gfs2_dinode *di;
 
@@ -1183,11 +1187,12 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 			if (error)
 				goto fail_end_trans;
 
-			ip->i_inode.i_atime.tv_sec = curtime;
+			ip->i_inode.i_atime = tv;
 
 			gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 			di = (struct gfs2_dinode *)dibh->b_data;
 			di->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
+			di->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
 			brelse(dibh);
 
 			gfs2_trans_end(sdp);
@@ -1290,6 +1295,9 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
 	str->di_entries = cpu_to_be32(di->di_entries);
 
 	str->di_eattr = cpu_to_be64(di->di_eattr);
+	str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
+	str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
+	str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
 }
 
 void gfs2_dinode_print(const struct gfs2_inode *ip)
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0443e255173..b46727275e5 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -104,6 +104,7 @@ static void init_vfs(struct super_block *sb, unsigned noatime)
 	sb->s_magic = GFS2_MAGIC;
 	sb->s_op = &gfs2_super_ops;
 	sb->s_export_op = &gfs2_export_ops;
+	sb->s_time_gran = 1;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 
 	if (sb->s_flags & (MS_NOATIME | MS_NODIRATIME))
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 919a661e4f7..9cc07f442ef 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -757,7 +757,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 		error = gfs2_meta_inode_buffer(ip, &dibh);
 		if (error)
 			goto out_end_trans;
-		ip->i_inode.i_ctime = CURRENT_TIME_SEC;
+		ip->i_inode.i_ctime = CURRENT_TIME;
 		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 		gfs2_dinode_out(ip, dibh->b_data);
 		brelse(dibh);
diff --git a/include/linux/gfs2_ondisk.h b/include/linux/gfs2_ondisk.h
index 2c4e24fb076..a44a6a078f0 100644
--- a/include/linux/gfs2_ondisk.h
+++ b/include/linux/gfs2_ondisk.h
@@ -259,8 +259,11 @@ struct gfs2_dinode {
 	struct gfs2_inum __pad4; /* Unused even in current gfs1 */
 
 	__be64 di_eattr;	/* extended attribute block number */
+	__be32 di_atime_nsec;   /* nsec portion of atime */
+	__be32 di_mtime_nsec;   /* nsec portion of mtime */
+	__be32 di_ctime_nsec;   /* nsec portion of ctime */
 
-	__u8 di_reserved[56];
+	__u8 di_reserved[44];
 };
 
 /*